The objective of this application is to prevent the complications of hemophilia and other bleeding disorders by prevention programs in the eight multidisciplinary centers in New England. This proposed program will be performed in conjunction with the national network of twelve federally funded regional networks. During the past ten years the regional networks, in conjunction with the Centers for Disease Control and Prevention (CDC), established a national network of treatment centers that have the capacity to serve as prevention centers. Multidisciplinary teams have been trained to implement prevention programs and research. A national database has been developed that collects demographic, clinical and quality of life data. This is the largest clinical database of rare bleeding disorders in the world. The regional program's overall goal for the next five years is in conjunction with the national network design prevention messages, strategies, and clinical trials and share the data with other relevant agencies, such as HRSA, MCHB, NHLBI, NHF and researchers and care providers of individuals. This will be accomplished by: 1) expanding the cohort through continued recruitment and observations of individuals with bleeding disorders including hemophilia A and Hemophilia B, von Willebrand disease, rare bleeding disorders, and women with bleeding disorders: (2) transition from paper submission of data to web-based (3) expand the database to collect data relevant to Woman's issues in coagulation, prophylaxis, inhibitor formation, utilization of treatment products and treatment regimes, obesity, and other important clinical information (4) maintain a regional administration that will support the established infrastructure and foster collaboration, (5) perform regional and national research utilizing the national database and (6) expand the current database to include relevant data on women's issues, obesity issues, rare bleeding disorders, and prophylaxis.